Typical cleanser formulations are designed to effectively and efficiently remove previously applied face powder, rouge, foundation bases, eyeshadow and lipstick. Surfactants are also particularly useful in removing waterproof makeup. In addition, cleansers remove dirt and oil that accumulate on the skin or in the hair. To achieve this, commercial facial cleansers, usually in the form of a gel, lotion or cream, use surfactant ingredients. Further, a refreshing feeling is experienced when the surfactant is in contact with water because it generates a bubbly foam. Unfortunately, many surfactants are drying to the skin and/or are irritating to user. Because they contain surfactants, many cleansers cannot be routinely used in or in some instances even around the eye area.
Surfactants can interfere with the natural protective lipid barrier of the skin. There are two sources of skin surface lipids making up this important barrier: the sebaceous glands and the epidermis. Lipids are a diverse croup of compounds, comprising triglycerides, diglycerides, ceramides, free fatty acids, wax esters, cholesterol and cholesterol esters, and squalene. The quantity and composition of the skin surface lipids differ from place to place on the body, and may to some extent be related to the number of sebaceous glands in a given area of the skin. The condition of the skin surface lipids may also be affected by an essential fatty acid deficiency. Additionally, the lipid barrier can be diminished by exposure to harsh detergents or soaps containing surfactants. Therefore, cleansers are desired which do not interfere with the lipid barrier of the skin, but which clean thoroughly and, feel cool and refreshing.
Another desirable characteristic of cleansing products is the refreshing feeling derived from a cooling sensation on the skin. To achieve a physiological cooling effect on the skin, it is known in the prior art to use, for example, menthol or other similar low volatile compounds. Other compositions used include acyclic secondary and tertiary sulphoxides and sulphones, p-menthane and its derivatives. However, these compositions have a strong odor and are not desirable for use on the skin. Therefore, a less traditional form is needed that will provide a refreshing and cooling feeling that is pleasant to use.
Consumers of cleansers not only desire a product that cleans deeply, they desire a product that "feels" like it cleans deeply. This feeling is achieved when a cleanser product is cool, refreshing and tingly or bubbly during its use. The present invention provides a self-foaming system that produces a cooling sensation, cleans deeply, and "feels" like it cleans deeply but does not interfere with the delicate lipid barrier of the skin.